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authorGabriele Mazzotta <gabriele.mzt@gmail.com>2015-04-25 19:52:37 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-06-06 08:19:36 -0700
commitedc8643179e9198aa11e7a505ac01a90e7859659 (patch)
tree2c330721634e994b4ec0fb5a1a53a04d8700e34d
parentd7ad68665c207a92d32a366a01481ebe3a6b2d57 (diff)
libata: Ignore spurious PHY event on LPM policy change
commit 09c5b4803a80a5451d950d6a539d2eb311dc0fb1 upstream. When the LPM policy is set to ATA_LPM_MAX_POWER, the device might generate a spurious PHY event that cuases errors on the link. Ignore this event if it occured within 10s after the policy change. The timeout was chosen observing that on a Dell XPS13 9333 these spurious events can occur up to roughly 6s after the policy change. Link: http://lkml.kernel.org/g/3352987.ugV1Ipy7Z5@xps13 Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/ata/libata-core.c15
-rw-r--r--drivers/ata/libata-eh.c3
-rw-r--r--include/linux/libata.h9
3 files changed, 26 insertions, 1 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 7f72ca0f0fc8..b1c0fcdf46fc 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6839,8 +6839,21 @@ u32 ata_wait_register(struct ata_port *ap, void __iomem *reg, u32 mask, u32 val,
*/
bool sata_lpm_ignore_phy_events(struct ata_link *link)
{
+ unsigned long lpm_timeout = link->last_lpm_change +
+ msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);
+
/* if LPM is enabled, PHYRDY doesn't mean anything */
- return !!(link->lpm_policy > ATA_LPM_MAX_POWER);
+ if (link->lpm_policy > ATA_LPM_MAX_POWER)
+ return true;
+
+ /* ignore the first PHY event after the LPM policy changed
+ * as it is might be spurious
+ */
+ if ((link->flags & ATA_LFLAG_CHANGED) &&
+ time_before(jiffies, lpm_timeout))
+ return true;
+
+ return false;
}
EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 6d8757008318..c6c77b767a8d 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3488,6 +3488,9 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
}
}
+ link->last_lpm_change = jiffies;
+ link->flags |= ATA_LFLAG_CHANGED;
+
return 0;
fail:
diff --git a/include/linux/libata.h b/include/linux/libata.h
index cf205c03d758..b84e786ff990 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -204,6 +204,7 @@ enum {
ATA_LFLAG_SW_ACTIVITY = (1 << 7), /* keep activity stats */
ATA_LFLAG_NO_LPM = (1 << 8), /* disable LPM on this link */
ATA_LFLAG_RST_ONCE = (1 << 9), /* limit recovery to one reset */
+ ATA_LFLAG_CHANGED = (1 << 10), /* LPM state changed on this link */
/* struct ata_port flags */
ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */
@@ -307,6 +308,12 @@ enum {
*/
ATA_TMOUT_PMP_SRST_WAIT = 5000,
+ /* When the LPM policy is set to ATA_LPM_MAX_POWER, there might
+ * be a spurious PHY event, so ignore the first PHY event that
+ * occurs within 10s after the policy change.
+ */
+ ATA_TMOUT_SPURIOUS_PHY = 10000,
+
/* ATA bus states */
BUS_UNKNOWN = 0,
BUS_DMA = 1,
@@ -785,6 +792,8 @@ struct ata_link {
struct ata_eh_context eh_context;
struct ata_device device[ATA_MAX_DEVICES];
+
+ unsigned long last_lpm_change; /* when last LPM change happened */
};
#define ATA_LINK_CLEAR_BEGIN offsetof(struct ata_link, active_tag)
#define ATA_LINK_CLEAR_END offsetof(struct ata_link, device[0])